Objectives To compare severity and clinical outcomes from Omicron as compared with the
Delta variant and to compare outcomes between Omicron sublineages. Methods We …

While it is now evident that Omicron is rapidly replacing Delta, due to a combination of
increased transmissibility and immune escape, it is less clear how the severity of Omicron …

Introduction Early reports showed that Omicron (BA. 1) SARS-CoV-2 could be less severe.
However, the magnitude of risk reduction of hospitalization and mortality of Omicron (BA. 1) …

Background A rapid increase in incidence of the SARS-CoV-2 Omicron variant (sub-lineage
BA. 1) occurred in France in December 2021, while the Delta variant was prevailing since …

Objective To assess the risk of covid-19 death after infection with omicron BA. 1 compared
with delta (B. 1.617. 2). Design Retrospective cohort study. Setting England, United …

Background Estimates of the severity of the SARS-CoV-2 omicron variant (B. 1.1. 529) are
crucial to assess the public health impact associated with its rapid global dissemination. We …

This retrospective multi-center matched cohort study assessed the risk for severe COVID-19
(combination of severity indicators), intensive care unit (ICU) admission, and in-hospital …

Background There is an urgent public health need to evaluate disease severity in adults
hospitalised with Delta and Omicron SARS-CoV-2 variant infections. However, limited data …

SARS‐CoV‐2 Omicron variant seemed to cause milder disease compared to previous
predominated variants. We aimed to conduct a meta‐analysis to assess the pooled …

The Omicron variant of SARS-CoV-2 was detected in October 2021 and exhibited high
transmissibility, immune evasion, and reduced severity when compared to the earlier …